By Brendan O'Brien
MILWAUKEE (Reuters) - Wisconsin Governor Scott Walker on Wednesday signed into law a bill repealing the state's 48-hour waiting period for handgun purchases, a measure supporters said will make buying a gun more convenient and opponents said will lead to increased violence.
Walker, a potential Republican candidate for president in 2016, also signed a bill that allows off-duty and retired law-enforcement officers to carry concealed guns on school grounds.
The signing of the repeal comes a week after a gunman killed nine worshippers in a historic African-American church in Charleston, South Carolina, in the latest mass shooting in the United States.
Walker said at the signing ceremony that the instant national background check system makes the waiting period law obsolete.
"This allows Wisconsin's law to catch up with the 21st century," he said.
Wisconsin's Republican-led legislature approved the repeal measure and the concealed carry expansion on June 9.
Both laws go into effect on Friday.
For 40 years, Wisconsin has required firearms dealers not to sell a handgun until 48 hours after a Wisconsin Department of Justice background check of the customer is completed.
In April, the National Rifle Association's legal action institute said on its website that the law had become an unnecessary time tax on the handgun buyer and the dealer.
After Wisconsin's repeal, nine states plus the District of Columbia require waiting periods for handgun purchases, ranging from three days to two weeks, according to the Law Center to Prevent Gun Violence, a gun-control advocacy group.
Gun-control advocates have said waiting periods provide time to cool off that can prevent impulsive violence or suicide.
"Instead of heeding the public's call for common sense reforms that keep us safer, Governor Walker and legislative Republicans have chosen to bolster their credentials with the NRA and other extreme right-wing interest groups," state Representative Lisa Subeck, a Democrat, said in a statement.
(Reporting by Brendan O'Brien in Milwaukee; Editing by Mohammad Zargham)